AI workload optimization startup Callosum raises $100M
London-based artificial intelligence startup Callosum Ltd. today announced that it has raised $100 million in funding.
Atomico led the seed investment with participation from Plural, DCVC, and the U.K. Sovereign AI Fund. The deal follows a $10.25 million raise in February.
Callosum offers a cloud service called Tailored Inference that helps developers increase the efficiency of their AI applications. According to the company, its technology can complete some inference tasks 3.7 times faster than GPT-5.6 Luna with better output quality. Callosum also promises to reduce infrastructure costs in the process.
The tasks that AI applications perform often comprise multiple steps. Tailored Inference turns the steps that make up a task into standalone software modules called blocks. From there, it sends each block to the AI model best equipped to run it. Simple tasks are routed to low-cost algorithms while more difficult work is performed by frontier models.
